This invention relates to a composite underbody cushioning and ventilating structure, more particularly to such structures where used as seat pads for occupants of motor vehicles. The invention also relates to an improved sheet material of general use formed from a single sheet of thermally formable plastic material.
The composite underbody cushioning and ventilating structure of the present invention is an improvement on the invention covered by U.S. Pat. No. 3,722,955 to Herbert H. Trotman, co-inventor in the present application.
Ventilated seat cushions for general use and for use in vehicles conventionally include a fabric cover having an exposed seating surface and a support structure which provides for ventilation while maintaining the fabric cover spaced above the vehicle seat to form a ventilating space under the body of the seat occupant. The cover fabric is generally foraminous to allow free passage of air into and out of the ventilating space. The cover material normally has a decorative appearance because it is exposed to view in use and this feature is also important from the standpoint of saleability. Representative patents in the prior art are: U.S. Pat. Nos. 3,162,487, 3,162,488, 3,940,183 and 4,143,916 none of which is anticipatory or taken singly or in any combination teach the present invention.
In the past, as illustrated in U.S. Pat. No. 3,722,955, these seat cushions had an upper side and a lower side, the upper side intended for body support contact and the lower side intended for spacing the body support side above the vehicle seat to permit ventilation between the two sides. The seat cushions preceding that of U.S. Pat. No. 3,722,955 had the disadvantage of the susceptibility of the cover fabric being subject to lateral scrubbing movement across the ventilating support structure. This scrubbing action resulted in the breakage of the cover fabric and other fast-wearing detrimental factors. The invention of U.S. Pat. No. 3,722,955 sought to correct the earlier faults in these types of seat cushions.
The present invention departs from previous concepts by providing a seat cushion which utilizes to the fullest advantage the characteristics of thermally moldable sheet plastic while at the same time resulting in a seat cushion which is reversible and has a decorative appearance on both sides.
The present invention can utilize a woven fabric of inherent porosity and ornate appearance on one side and an imperforate, three-dimensionally formed plastic sheet for the other side, the ventilating characteristics of the plastic sheet being achieved by depressions or wells in the surface of the sheet, these wells when considered from the inner side of the plastic sheet also acting to space the two sheets apart in coaction with an optional padding or filler material between the two sheets. The decorative appearance on the plastic sheet side of the seat of the present invention is achieved by simulating woven cane on the other side of the plastic sheet, such as illustrated in U.S. Pat. No. 3,722,955 but in the present invention the openings in the woven cane are openings in appearance only, this appearance being achieved by the imperforate depressions or wells. As mentioned above, these same depressions or wells form on the inner side of the plastic sheet protuberances which space the two cover sheets apart in coaction with the padding or filler material, where the latter is also used. Thus these elements perform a dual function in the composite seat cushion.
An important aspect of the present invention is the molded form of the imperforate plastic sheet which utilizes thin, thermally formable plastic sheet in the most efficient manner in addition to achieving the decorative appearance and the spacing protuberances.
Accordingly, an important object of the present invention is to provide a reversible ventilating seat cushion having two decorative sides and excellent ventilation characteristics.
A further object of the present invention is to produce a thin, thermally formable plastic sheet formed into the most efficient configuration relative to strength of the plastic sheet and its use for many purposes.
Other objects of the present invention will appear from the following detailed description which, in connection with the accompanying drawings, discloses the preferred embodiment of the invention for purposes of illustration only and not for determination of the limits of the invention. For defining the scope of the invention reference will be made to the appended claims.